1. Begin with the expression in the innermost parentheses or brackets and work your way out. Simplify all numbers with exponents, working from left to right; then perform all multiplications and divisions from left to right; then perform all additions and subtractions, from left to right. parentheses, exponents, multiply, divide, add, subtract Back

2. A set is a collection of objects or things. Ex: {2,4,6,8}

A union of two sets A and B, written A U B, is the set consisting of all the elements that are in A OR B. Ex: if A={0,1,2} and B={2,3}, then A U B = {0,1,2,3}

An intersection of two sets A and B, written A W B, is the set consisting of all the elements that are in A AND B. Ex: if A={0,1,2} and B={2,3}, then A W B = {2}

A is a subset of B, written A z B, if all the elements in set A are also in set B.